Ext-gen migrate doesn't work : Found Extra positional on npm run dev

I have a porject done with Extjs 6.7 classic.
Iw ant to migrate it, in order to use npm.

I foolow the docs as written =>
npm install -g @sencha/ext-gen
Then => ext-gen migrate
And npm install
At the End: npm run dev
But I have the following error :

i ｢wds｣: webpack output is served from /x"!
i ｢wds｣: Content not from webpack is served from ./:
i ｢wds｣: 404s will fallback to /index.html
i [ext]: [ERR] Found extra positional argument desktop
******************************************satisfied:
i [ext]: Found extra positional argument desktop

When I run the npw sencha app watch, I got te following
[ERR] Cannot satisfy requirements for "ux"!